1. Field of the Invention
The present invention relates to an electronic still camera and, more particularly, to an electronic still camera having a base clip circuit with variable operation characteristics.
2. Description of the Prior Art
In general, electronic still cameras suffer from a common drawback in that the dark current component in a pixel signal from each pixel of an imaging device increases as the charge storage time, i.e., the shutter opening time, increases, with the result that the dynamic range of the pixel signal is undesirably restricted. The noise caused by the dispersion of dark current in each pixel is increased as the charge storage time increases, so that the S/N ratio is disadvantageously reduced.
Electronic still cameras usually incorporate base clip circuits for clipping image signals at base level. Such base clip circuits, however, are not designed to allow their clipping characteristics to be varied. Namely, the clipping characteristics of these base a clip circuits are kept constant, regardless of a change in the dark current level. Thus, the known electronic cameras with such base clip circuits can not eliminate the reduction in the S/N ratio attributable to a change in the dark current level.